Sodium metavanadate dispersed in Polyaniline composite matrix film for sensing application

Abstract

Composite of sodium metavanadate (NaVO3) and polyaniline (PANI) was formed by in-situ chemical polymerization in one step. Characterization techniques such as X-Ray diffraction, Scanning electron micrograph, and Fourier transform infra-red spectra confirm mixed phase of formation NaVO3inPANI emeraldine salt. Conductivity decreases with an increase in wt of NaVO3in PANI, the conductivity increases with temperature is due to an increase in disorderliness, induction of conformational changes within the composite, and thermally activated exponential behavior. The composites have shown high sensitivity in the low humidity range with the decrease in electrical resistance when exposed to humidity in the range of 20 to 50% RH. The moisture absorption is due to capillary condensation within the composite, which decreases the conductivity of the matrix with humidity. The transfer of charges from sensing material to analyte gas (donor) by penetration with enlargement of the polymer composites decreases the conductivity with the concentration of LPG.